This paper presents a control technique for improving the thermodynamics characteristic of the hydrogen gas within metal hydride(MH) reactor by heating/cooling with a thermoelectric module, Peltier element. Practically, the uncertainty of the parameters, such as unexpected outside temperature of the reactor. Additionally, the complicated problem of the integrated system model, Peltier and MH reactor, make the system to be nonlinear which makes it hard to use the conventional controller like proportional+integral+derivative, PID, or conventional fuzzy control to improve dynamic response. To obtain a high performance of the thermal management for the MH reactor, the fuzzy adaptive PID is developed. The fuzzy rules based on the knowledge of MH system are used to adapt the gain parameters of the PID control. The mathematical model of the MH thermal system is determined for using as the knowledge base for fuzzy rules. The experimental results show the effectiveness of the proposed technique that compared to conventional control.