It is necessary for improving the safety of a swing-type window to evaluate the impact force caused by the wind flowing along a wall in the stopper part of the window. The strong wind test was performed in order to measure the impact force induced by a wind, and the characteristic of the wind energy and the impact force were clarified. The evaluation method of the impact force based on simple oscillation was proposed, and it is confirmed that the impact force by the proposed method is good agreement with the impact force by the drop weight test. It is considered that the proposed evaluation method is useful for the safety design of the swing-type window.