A stirrup having an opening and closing function, which is intended to be coupled to a saddle so that a rider's foot may rest thereon, the stirrup comprising: a main body part, a hook part to which a saddle strap may be fastened, a support part connected to a foot plate base plate, and an open part formed on one side thereof; wherein: - an opening and closing part, is detachably connected to a coupling part of the main body part; - a wire part is connected to one end of the opening and closing part and the main body part; - a magnetic body is disposed on the other end of the opening and closing part, allowing the end to be attachable to the main body part by means of magnetic force; characterized in that said main body part comprises: • an extension part, extending downwards from the upper side of the open part and connected to the wire part; • and said coupling part, extending upwards from the lower side of the open part, on which a removable part is disposed that is combinable with the magnetic body by means of the magnetic force and wherein one end of said wire part is combined with the extension part, the other end thereof being elastically supported by an elasticity-providing part in a flexible space formed in the opening and closing part; said elasticity-providing part, when the opening and closing part opens and the foot is completely freed, causing the wire part to shrink, so that the upper end of the opening and closing part is combined with the extension part and the lower end of the opening and closing part comes close to the coupling part, allowing the magnetic body to be detachably coupled to the removable part by means of magnetic force. - an opening and closing part, is detachably connected to a coupling part of the main body part; - a wire part is connected to one end of the opening and closing part and the main body part; - a magnetic body is disposed on the other end of the opening and closing part, allowing the end to be attachable to the main body part by means of magnetic force; characterized in that said main body part comprises: • an extension part, extending downwards from the upper side of the open part and connected to the wire part; • and said coupling part, extending upwards from the lower side of the open part, on which a removable part is disposed that is combinable with the magnetic body by means of the magnetic force and wherein one end of said wire part is combined with the extension part, the other end thereof being elastically supported by an elasticity-providing part in a flexible space formed in the opening and closing part; said elasticity-providing part, when the opening and closing part opens and the foot is completely freed, causing the wire part to shrink, so that the upper end of the opening and closing part is combined with the extension part and the lower end of the opening and closing part comes close to the coupling part, allowing the magnetic body to be detachably coupled to the removable part by means of magnetic force. • an extension part, extending downwards from the upper side of the open part and connected to the wire part; • and said coupling part, extending upwards from the lower side of the open part, on which a removable part is disposed that is combinable with the magnetic body by means of the magnetic force and wherein one end of said wire part is combined with the extension part, the other end thereof being elastically supported by an elasticity-providing part in a flexible space formed in the opening and closing part; said elasticity-providing part, when the opening and closing part opens and the foot is completely freed, causing the wire part to shrink, so that the upper end of the opening and closing part is combined with the extension part and the lower end of the opening and closing part comes close to the coupling part, allowing the magnetic body to be detachably coupled to the removable part by means of magnetic force.