To provide a stopper applicable to an angled drill to solve the problem that when drilling work is performed to make a hole of a given depth using an electric drill with a stopper attached thereto, a conventional stopper being a single long bar tool cannot be applied directly to an angled drill for drilling work in a narrow space.

A flexible bar constructed by connecting together a number of joint pieces 10a is used as a stopper 10, the joint pieces 10a having receiving portions 10b with hemispherical recessions and spherical connecting portions 10c fitted into the receiving portions 10b. This stopper 10 can be bent at an any given position, and, therefore, can be applied to an angled drill 1 without impairing its function.