Abstract: Disclosed is a polyamide ester which comprises a plurality of specific amide ester recurring units including, in a specific ratio, recurring units containing a tetravalent benzene group and recurring units containing a tetravalent diphenyl ether group, and which is adapted to be converted to a polyimide in a coating form by heat-curing, wherein the polyimide coating exhibits a residual stress of 33 MPa or less as measured with respect to a 10 &mgr;m-thick polyimide coating formed on a silicon substrate. Also disclosed is a polyamide ester composition comprising a plurality of different polyamide esters, wherein the plurality of different polyamide esters collectively contain, in a specific ratio, the recurring units containing a tetravalent benzene group and the recurring units containing a tetravalent diphenyl ether group.