To provide a method for purifying a vinyl type monomer, capable of removing/reducing a mercaptan-based compound from a vinyl type monomer containing a very small amount of the mercaptan-based compound as an impurity in a short time.

In this method for purifying a vinyl type monomer containing a mercaptan-based compound as an impurity, a process for using a metal compound containing at least one kind of an element selected from the group consisting of copper, cobalt, nickel and manganese and a chlorine-containing compound as a catalyst and bringing the vinyl type monomer containing the mercaptan-based compound in a liquid state into contact with molecular oxygen in the presence of a phenol-based polymerization inhibitor is included.