$H\otimes l^{2}(\Gamma)\cong\bigoplus\limits_{g\in \Gamma}H$

Question

I have no idea of proving $H\otimes l^{2}(\Gamma)\cong\bigoplus\limits_{g\in \Gamma}H$,where H is a hilbert space,$\Gamma$ is a discrete group, $l^{2}(\Gamma)$ is the set of all complex valued square summable fuctions on $\Gamma$.