A stairway lift is provided on the treads of a stairway along a sidewall. A guide of the lift is provided on the treads along the sidewall so that a space is formed between the sidewall and the guide. The guide has a first side that faces the sidewall, a first rail provided on the first side, a chain rack on the first side that extends along the sidewall and a second side that faces away from the sidewall. A mobile body is supported by the first rail in the space formed between the sidewall and the guide. The mobile body has a drive sprocket engageable with the chain rack and an electric motor coupled with the drive sprocket for rotatively driving the drive sprocket. A carrier is provided for carrying a person or object to be moved along the stairway. A coupling arrangement couples the mobile body and the carrier so that the carrier is removably supported by the mobile body on the second side of the guide and guided for travel by the guide. The carrier can thus ascend and descend the stairway together with the mobile body.