A handheld electronic device including a first body, a second body and a moving mechanism is provided. The second body is stacked under the first body. A side of the second body facing the first body has a concave portion. The moving mechanism includes a first sliding member, a second sliding member and an elevating mechanism. The first sliding member is fixed to the first body. The second sliding member is slidingly disposed at the first sliding member. The elevating mechanism is connected between the second body and the second sliding member. After the first sliding member drives the first body to shift relatively to the second body to reach the concave portion, the first body compresses the elevating mechanism and enters the concave portion.