To provide a socket for a chemical anchor capable of being loosened without using a tool.

A socket body A is fitted between the center of a hammer drill and a chemical anchor bolt 4 buried in concrete, a mechanism for tightening to or loosening from the split nut engaged with the thread part of the anchor bolt by roller pins 13 fitted to the inner peripheral surface of the socket body is installed around the chemical anchor bolt inserted into the socket body, and retaining pieces 7 and 9 having several steel balls installed therebetween are installed on the lower side of the split nut.