Error Estimation for Stationary Galerkin Method for Semilinear Parabolic Equation with Changing Direction of Time

In a cylindrical domain $Q\subseteq R^{n+1}$ the first boundary value problem for semilinear parabolic equation with changing direction of time is considered. It is developed stationary Galerkin method for the study of boundary value problem. It is proved the existence and uniqueness of solution of the first boundary value problem in the space $W_{2}^{2,1}(Q)$. Error estimation for stationary Galerkin method is obtained in the norm of the space $W_{2}^{1,0}(Q)$ through eigenvalues of selfadjoint spectral problem for the elliptic equation of second order.