Provided is a method for producing myocardial cells from pluripotent stem cells. The myocardial cell production method provided by the present invention includes supplying an artificially produced synthetic peptide to a cell culture that contains pluripotent stem cells. The synthetic peptide is a peptide that contains a myocardial cell differentiation-inducing peptide sequence that induces pluripotent stem cells into myocardial cells. The myocardial cell differentiation-inducing peptide sequence is an amino acid sequence selected from the group consisting of (i) an amino acid sequence constituting the signal peptide of any protein belonging to the amyloid precursor protein (APP) family, (ii) a partial amino acid sequence of the amino acid sequence according to (i), and (iii) a modified amino acid sequence from the amino acid sequence according to (i) or (ii).