A medium conveying device includes a first guide member, a second guide member, a conveying member, and a support member. The first guide member guides one face of a medium to be conveyed and opposed to the one face when the medium is conveyed. The second guide member guides the other face of the medium and is opposed to the other face when the medium is conveyed, the second guide member being movable between a close position and an open position. The conveying member is provided in a conveying passage formed by the first guide member and the second guide member being at the close position in order to convey the medium in the conveying passage. The support member keeps the second guide member at the open position and is provided at a position outer than the second guide member in a direction that the medium is conveyed. When the second guide member is at the open position, the medium in the conveying passage is removable from the conveying passage.