The present invention relates to a novel bisimide compound useful as an acid generator for a chemically amplified resist composition used in manufacturing of semiconductor element and the like or a raw material for synthesizing heat resistant polymers, an acid generator and a resist composition using said compound and a method for pattern formation using said composition, and further relates to a synthetic n intermediate for a bisimide compound and a bis(N-hydroxy)phthalimide compound useful as an intermediate for a functional compound such as a heat resistant polymer or photosensitive material, and provides a bisimide compound shown by the general formula [1]: ##STR00001## (wherein R and A.sub.1 are as defined in claim 1).