diff --git a/src/parser/core-parser.pegjs b/src/parser/core-parser.pegjs
index f6c80e2..8f529f0 100644
--- a/src/parser/core-parser.pegjs
+++ b/src/parser/core-parser.pegjs
@@ -42,7 +42,7 @@ inline
 	/ inlineCode
 	/ mathInline
 	// / mention
-	// / hashtag
+	/ hashtag
 	// / url
 	// / link
 	/ customEmoji
@@ -253,6 +253,26 @@ mathInline
 }
 
 
+// inline: hashtag
+
+hashtag
+	= "#" content:hashtag_content
+{
+	return createTree('hashtag', { hashtag: content });
+}
+
+hashtag_content
+	= (![\s!"#$%&'*+,\-./:;<=>?@\\^_`{|}~【】＜＞] (hashtag_bracket / hashtag_char))+ { return text(); }
+
+hashtag_bracket
+	= "(" hashtag_content* ")"
+	/ "[" hashtag_content* "]"
+	/ "「" hashtag_content* "」"
+
+hashtag_char
+	= ![()\[\]「」] CHAR
+
+
 // inline: custom emoji
 
 customEmoji