diff --git a/crates/uroborosql-fmt/src/cst/expr/unary.rs b/crates/uroborosql-fmt/src/cst/expr/unary.rs
index d9f301b..cc79c0d 100644
--- a/crates/uroborosql-fmt/src/cst/expr/unary.rs
+++ b/crates/uroborosql-fmt/src/cst/expr/unary.rs
@@ -51,7 +51,10 @@ impl UnaryExpr {
         let mut result = String::new();
 
         result.push_str(&self.operator);
-        result.push('\t');
+        // `NOT` のときは空白が必要
+        if self.operator.to_uppercase().as_str() == "NOT" {
+            result.push('\t');
+        }
         result.push_str(&self.operand.render(depth)?);
 
         Ok(result)
diff --git a/crates/uroborosql-fmt/src/visitor/expr.rs b/crates/uroborosql-fmt/src/visitor/expr.rs
index ff37521..e1a68eb 100644
--- a/crates/uroborosql-fmt/src/visitor/expr.rs
+++ b/crates/uroborosql-fmt/src/visitor/expr.rs
@@ -11,6 +11,7 @@ mod is;
 mod paren;
 mod subquery;
 mod type_cast;
+mod unary;
 
 use tree_sitter::TreeCursor;
 
@@ -137,6 +138,10 @@ impl Visitor {
             "all_some_any_subquery_expression" => {
                 Expr::Aligned(Box::new(self.visit_all_some_any_subquery(cursor, src)?))
             }
+            "unary_expression" => {
+                let unary = self.visit_unary_expr(cursor, src)?;
+                Expr::Unary(Box::new(unary))
+            }
             _ => {
                 // todo
                 return Err(UroboroSQLFmtError::Unimplemented(format!(
diff --git a/crates/uroborosql-fmt/src/visitor/expr/unary.rs b/crates/uroborosql-fmt/src/visitor/expr/unary.rs
new file mode 100644
index 0000000..7d09193
--- /dev/null
+++ b/crates/uroborosql-fmt/src/visitor/expr/unary.rs
@@ -0,0 +1,34 @@
+use tree_sitter::TreeCursor;
+
+use crate::{
+    cst::{unary::UnaryExpr, Location},
+    error::UroboroSQLFmtError,
+    visitor::{ensure_kind, Visitor},
+};
+
+impl Visitor {
+    pub(crate) fn visit_unary_expr(
+        &mut self,
+        cursor: &mut TreeCursor,
+        src: &str,
+    ) -> Result<UnaryExpr, UroboroSQLFmtError> {
+        // cursor -> unary_expression
+
+        let mut loc = Location::new(cursor.node().range());
+
+        cursor.goto_first_child();
+        // cursor -> op ("+", "-", "!!", "~", "@", "|/", "||/", "NOT")
+        let operator = cursor.node().utf8_text(src.as_bytes()).unwrap();
+
+        cursor.goto_next_sibling();
+        // cursor -> _expression
+
+        let operand = self.visit_expr(cursor, src)?;
+        loc.append(operand.loc());
+
+        cursor.goto_parent();
+        ensure_kind(cursor, "unary_expression", src)?;
+
+        Ok(UnaryExpr::new(operator, operand, loc))
+    }
+}
diff --git a/crates/uroborosql-fmt/testfiles/dst/select/unary.sql b/crates/uroborosql-fmt/testfiles/dst/select/unary.sql
new file mode 100644
index 0000000..9dc2f63
--- /dev/null
+++ b/crates/uroborosql-fmt/testfiles/dst/select/unary.sql
@@ -0,0 +1,39 @@
+select
+	+5	as	positive_value
+;
+select
+	+5	as	positive_value
+;
+select
+	-10	as	negative_value
+;
+select
+	-10	as	negative_value
+;
+select
+	not	true	as	not_true
+;
+select
+	~5	as	bitwise_not
+;
+select
+	~5	as	bitwise_not
+;
+select
+	@-5	as	absolute_value
+;
+select
+	@-5	as	absolute_value
+;
+select
+	|/25	as	square_root
+;
+select
+	|/25	as	square_root
+;
+select
+	||/8	as	cube_root
+;
+select
+	||/8	as	cube_root
+;
diff --git a/crates/uroborosql-fmt/testfiles/src/select/unary.sql b/crates/uroborosql-fmt/testfiles/src/select/unary.sql
new file mode 100644
index 0000000..1a9a502
--- /dev/null
+++ b/crates/uroborosql-fmt/testfiles/src/select/unary.sql
@@ -0,0 +1,19 @@
+select +5 as positive_value
+select + 5 as positive_value
+
+select -10 as negative_value
+select - 10 as negative_value
+
+select not true as not_true
+
+select ~5 as bitwise_not
+select ~ 5 as bitwise_not
+
+select @-5 as absolute_value
+select @ -5 as absolute_value
+
+select |/25 as square_root
+select |/ 25 as square_root
+
+select ||/8 as cube_root
+select ||/ 8 as cube_root
\ No newline at end of file