To provide a tool replacement mechanism which does not force a worker to take an irrational posture due to excessive load on the arm and the waist because the weight of a tool is almost applied to the worker in manual work for replacing a tool in a tool magazine of a machine tool.

This tool replacement mechanism of the tool magazine is composed of: a rocking tool pot 3 provided on a plurality of connected chain links and supported by a support member rockable in the direction orthogonal to the moving direction in a tool replacement position; and a pot rocking means provided on the support member, abutting on the outer peripheral surface of the circulating rocking tool pot from inside to push outward the tool pot round the fulcrum and energize the same to be inclined.