The present invention is the appearance of the crown portion cockle cap when reducing the size, by making it possible to increase or reduce the overall volume to be, more particularly, if the standing crown lower circumferential size and a crown portion of the portion supporting the crown portion to bend about the adjustment cap size relates to a sizing cap can be prevented from being damaged, in the cap, including the which cover the head crown portion, visor portion which is attached to crown the front of the crown portion of the two is provided to be connected to each other at the front both sides of the front cover cloth and; Is provided with connections to protrude rearward from the respective rear ends of the front cover cloth, each of the upper two sides is two sides is connected to the upper portion of the front cover cloth and a cloth cover; Is provided to be connected to each other on the rear sides, the upper portion is coupled to the upper portion of the side cover cloth for the top and both sides of the front cover cloth, each of the front is opened configuration as in the outer cloth with the rear and the lower packed inside and has two shallow rear cover cloth is inserted portion is formed to be inserted into the shift-side cover; It characterized in that it comprises; sizing connection means for connection possibly separated by inserting the side of the cover cloth to the cloth insert.