An object of the present invention is to provide a myocardial progenitor cell that is specifically induced to differentiate into a cardiomyocyte, and a method for preparing the myocardial progenitor cell. A method for preparing a CD82-positive cell includes, in sequence, a step (a) of obtaining stem cells, a step (b) of subjecting the stem cells to induction treatment of differentiation into cardiovascular cells, and a step (c) of separating, from the stem cells having been subjected to the induction treatment of differentiation in the step (b), a CD82-positive cell being negative for at least one cell surface marker selected from CD73, CD44, CD105, CD121a, CD18, and CD120a. This method enables preparation of a CD82-positive cell for use as a myocardial progenitor cell.
