If \( f(x) \) is an even function and the point \( (x, y) \) is on the graph of \( f(x) \), then by the definition of an even function, it satisfies the property \( f(-x) = f(x) \). Therefore, the point \( (-x, y) \) must also be on the graph of \( f(x) \).
In summary, if \( (x, y) \) is on the graph of the even function \( f(x) \), then the point \( (-x, y) \) is also on the graph.