Abstract: A rotary type extension/retraction device includes a body member, a movement member, a spring member, a protrusion and a cam groove. The cam groove has a first fitting groove configured to hold the movement member in a state protruding from a cylindrical part of the body member, a second fitting groove configured to hold the movement member in a state pulled in the cylindrical part, a first guide groove configured to guide the protrusion from the first fitting groove to the second fitting groove, and a second guide groove configured to guide the protrusion from the second fitting groove to the first fitting groove. The first fitting groove, the first guide groove, the second fitting groove and the second guide groove are arranged circumferentially along an inner periphery of the cylindrical part in this order.