A clip, comprising: a male member including a head portion and a shaft portion provided below the head portion; a female member including a locking leg portion forming an insertion hole into which the shaft portion is inserted, and a flange portion provided on an upper-side periphery of the locking leg portion; and an engagement device restraining the head portion in the flange portion substantially at the same time when the locking leg portion comes to a use state by pushing the shaft portion into the insertion hole, wherein the engagement device is formed by a claw portion provided in one of the head portion and the flange portion, and a hole portion provided in another of the head portion and the flange portion, and engaging the claw portion, and the claw portion in a use state projects to a first piece portion which is elastically moveable, and one portion of a hole forming portion defining the hole portion is elastically moveable by the hole portion, said clip being characterized in that a second piece portion of the head portion, which comprises said claw portion elastically moves by a slit passing through the head portion, and the flange portion includes a periphery wall for housing the head portion, and the periphery wall has the hole portion to pass through approximately horizontally, the head portion has preferably an approximately rectangular shape, the shaft portion is provided to project at a center of a lower face of the head portion in an approximately rectangular column shape, and the respective slits have a straight groove shape, and in the periphery wall, there are provided notch portions on both sides notched in an arc shape; and elastically moveable said first piece portions provided corresponding to both notch portions, each first piece portion has respectively one hole portion, and can move to be displaced by the presence of the hole portion passing through the inside and outside of the periphery wall. a male member including a head portion and a shaft portion provided below the head portion; a female member including a locking leg portion forming an insertion hole into which the shaft portion is inserted, and a flange portion provided on an upper-side periphery of the locking leg portion; and an engagement device restraining the head portion in the flange portion substantially at the same time when the locking leg portion comes to a use state by pushing the shaft portion into the insertion hole, wherein the engagement device is formed by a claw portion provided in one of the head portion and the flange portion, and a hole portion provided in another of the head portion and the flange portion, and engaging the claw portion, and the claw portion in a use state projects to a first piece portion which is elastically moveable, and one portion of a hole forming portion defining the hole portion is elastically moveable by the hole portion, said clip being characterized in that a second piece portion of the head portion, which comprises said claw portion elastically moves by a slit passing through the head portion, and the flange portion includes a periphery wall for housing the head portion, and the periphery wall has the hole portion to pass through approximately horizontally, the head portion has preferably an approximately rectangular shape, the shaft portion is provided to project at a center of a lower face of the head portion in an approximately rectangular column shape, and the respective slits have a straight groove shape, and in the periphery wall, there are provided notch portions on both sides notched in an arc shape; and elastically moveable said first piece portions provided corresponding to both notch portions, each first piece portion has respectively one hole portion, and can move to be displaced by the presence of the hole portion passing through the inside and outside of the periphery wall.