A simple yet robust and fast time integration method is proposed for efficiently solving stiff chemical kinetic ordinary differential equations. The proposed method is based on a general formula which preserves the conservation laws for any integration operators con- structed using the Lagrange multiplier method. A quasi-steady-state approxixmation is used as the integrator. The time step size is automatically controlled by using a Lagrange multiplier so that the error, which is caused by the Lagrange multiplier method, is small. The results of several ignition problems demonstrate the robustness and accuracy of the proposed method in comparison with other integration methods such as a implicit inte- gration method (VODE), a multi time-scalse method (MTS), and a modified CHEMEQ2. The proposed method, named ERENA, provides the fastest performance for the most of conditions used in this study.