Abstract: It is an object of the present invention to provide a slot-in type disk apparatus which can further be thinned without deteriorating strengths of a lever and a base body. The slot-in type disk apparatus in which a base body 10 and a lid constitute a chassis sheath, a disk-insertion opening 11 into which a disk is directly inserted is formed in a front surface of the chassis sheath, wherein an opening 2 is formed in a portion of the base body 10, a plate which is thinner than the base body 10 is mounted to the opening 2, thereby forming a space which is recessed more than a surface of the base body 10 on the side of the lid, and a position above the space is a movement range of a lever which pulls in the disk.