A penis exercise machine includes an attaching portion main body which is abutted against and mounted on a body surface side of a periphery of a man's penis, a pair of support rods whose one ends are turnably mounted on a surface of the attaching portion main body such that the support rods are located on both sides sandwiching the penis, a support portion which is mounted such that it can be attached to both end sides of the support rods and which is abutted such that a glans on the side of a tip end of the penis is supported, and a holding belt of the glans mounted on the support portion.