In recent decade, many researches has been done on job shop scheduling problem with sequence dependent setup times (SDSJSP), but with respect to the knowledge of authors in very few of them the assumption of existing inseparable setup has been considered. Also, in attracted metaheuristic algorithms to this problem the Particle Swarm Optimization has not been considered. In this paper, the ISDSJSP with makespan minimization is considered. For this problem an MILP model has been developed and a PSO algorithm has been applied to solve it. In order to improve final solution obtained by PSO a simulated annealing algorithm has been applied. The proposed hybrid algorithm (HPSO) has been applied on some generated benchmark problems and the results indicate the effectiveness and efficiency of the proposed hybrid PSO with respect to two other algorithms