The temperature dependent Quantum Master Equation is derived by generalizing the van Kampen method. Starting with a stochastic Sroedinger equation and taking into account the finite quantum correlation time of the thermal bath we have proved the Fluctuation-Dissipation like relation at the step of the Shroedinger-Langevin picture. This fact preserves the normalization of the density matrix. Two particular cases are studied: the two level atom and the harmonic oscillator, both in interaction with a thermal bath of oscillators. We have stressed the usefulness of this picture to study nonequilibrium many-body quantum statiscial mechanic systems.