A buckle includes a male buckle member and a female buckle member. The male buckle member has: a male buckle body having a first coupler at a first end; a guide formed at a second end of the male buckle body and having a first guide surface; and an elastic arm formed at the second end of the male buckle body at a predetermined distance from the guide, being bendable toward the guide, and having a projection and a second guide surface. The female buckle member has: a female buckle body having a second coupler at a first end; a housing formed at a second end of the female buckle body and having a space for receiving the guide and the elastic arm; and a side hole formed to secure the projection of the elastic arm when the guide and the elastic arm are inserted in the space.
