A polyimide silicone having in the molecule a phenolic hydroxy group in which a part or all of hydrogen atoms are substituted with an acid labile group is provided. The polyimide silicone comprises the unit represented by the formula (1): wherein X is a tetravalent group at least a part of which is a tetravalent organic group represented by the formula (2): wherein R1 is a monovalent hydrocarbon group, R2 is a trivalent group, and n is an integer of 1 to 120 on average; and Y is a divalent organic group at least a part of which is a divalent organic group having a phenolic hydroxy group in which a part or all of hydrogen atoms are substituted with an acid labile group represented by the formula (3): wherein R3 and R4 are a hydrogen atom or an alkyl group, and R5 is an alkyl group, an aryl group, or an aralkyl group. R3 and R4, R3 and R5, or R4 and R5 may be bonded to each other to form a ring together with the carbon atom or the carbon atom and the oxygen atom to which they are bonded with the proviso that the R3, R4, and R5 are independently an alkylene group.