Provided is a method for preparing an electroconductive mayenite type compound with good properties readily and stably at low cost. A production method of an electroconductive mayenite type compound comprising a step of subjecting a precursor to heat treatment, is a method for preparing an electroconductive mayenite type compound, comprising a step of subjecting a precursor to heat treatment; wherein the precursor is a vitreous or crystalline material, which contains Ca and Al, in which a molar ratio of (CaO:Al2O3) is from (12.6:6.4) to (11.7:7.3) as calculated as oxides, and in which a total amount of CaO and Al2O3 is at least 50 mol %, and wherein the heat treatment is heat treatment comprising holding the precursor at a heat treatment temperature T of from 600 to 1415° C. and in an inert gas or vacuum atmosphere with an oxygen partial pressure PO2 in a range of PO2≦105×exp[{−7.9×l04/(T+273)}+14.4] in the unit of Pa.