PURPOSE: To prevent deterioration and warps, by specifying the coarseness of the surface where an insert made of a rigid member contacts a holder made of thermotropic liquid crystal polymer.

CONSTITUTION: A holder 1 made of thermotropic liquid crystal polymer is insert-molded so as to press an insert 2 equipped with a heater 3 and thus a hot plate is formed. The holder 1 is pressurized toward the inside by means of the proper orientation of the liquid crystal polymer and by that, the holder 1 is stuck to the insert 2. The side of ceramic stuck to the hot plate is processed by a file to make coarser than the indication of coarseness of 50-S by one triangle signal stipulated in JIS-B0031. The holder 1 and the insert 2 are fixed more closely by the coarseness in addition to the pressure. There is no warps and deterioration because no adhesive is employed.