The present disclosure relates to an oven having a guide member capable of automatically withdrawing an oven rack from the inside of a cooking chamber when a door is opened and a rail detachably coupled to the cooking chamber and the oven rack to move the oven rack in the front-rear direction. The oven includes a main body, a cooking chamber provided inside the main body and having an open front side, a door rotatably coupled to the main body to open and close the cooking chamber, an oven rack provided inside the cooking chamber to be movable in the front-rear direction and supporting a plurality of shelves, and a guide member connected to the oven rack according to opening and closing of the door to guide the oven rack to be moved in the front-rear direction, and separated from the oven rack when the door is completely opened.