A shielding blanket design in a fusion reactor such as ITER (International Thermonuclear Experimental Reactor) has been proposed to be a modular structure integrated with the first wall. In terms of the fabrication, HIP (Hot Isostatic Pressing) method has been proposed for the joining of dispersion strengthened copper (DS-Cu) and type 316L stainless steel (SS316L) at FW. High heat flux tests of HIP bonded DS-Cu/SS316L first wall panel were performed at Particle Beam Engineering Facility in JAERI to investigate its thermo-mechanical performance. They consisted of four test campaigns. The former two campaigns simulated ITER normal operation conditions in terms of the temperature and strain at the HIP bonded interfaces between DS-Cu and SS316L, respectively. The latter two simulated disruption conditions. Under normal heat flux conditions, temperature responses of the first wall panel measured by the thermocouples agreed very well with those predicted by FEM analyses. On the other hand, ejection of a number of small particles from DS-Cu surface was observed during the last campaign with the high heat flux simulating disruptions.