A thumb pick comprises a pick body for a guitar and a belt body which fixes the pick body to a finger. The pick body is extended integrally with a protruding portion for picking the strings from a base end portion made into contact with the thumb. The belt body is separately formed from the belt body. Both end portions of the belt body is adjustably connected to the pick body. There is provided a cut bent from the protruding portion to the base end portion of the pick body, a substantially tongue-like connecting piece is formed within the cut, and the connecting piece and the one end portion of the belt body 2 are detachably connected. with such construction, a disadvantage of displacing the position of the thumb pick by heat generation and perspiration of the fingers during a performance is solved, and picking suitable for each kind of performing method becomes possible.