A charging device for charging a first game controller and a second game controller, wherein: the first game controller includes a first rail member configured for allowing the first game controller to be attached to the charging device; the second game controller includes a second rail member configured for allowing the second game controller to be attached to the charging device; the charging device includes: a support section; a first slide member in an area of the support section toward a first side in a predetermined direction, the first slide member being configured to slidably engage with the first rail member in a first slide direction; and a second slide member in an area of the support section toward a second side in the predetermined direction, the second slide member being configured to slidably engage with the second rail member in a second slide direction; the first slide member includes: a first facing portion having a first facing surface facing the second side; and a first terminal on the first facing surface, which first terminal is configured to be electrically connected to the first game controller; the second slide member includes: a second facing portion having a second facing surface facing the first side; and a second terminal on the second facing surface, which second terminal is configured to be electrically connected to the second game controller; the charging device includes a power supply control section configured to supply power, which is supplied from outside the charging device, to the first game controller via the first terminal and to the second game controller via the second terminal; the first facing portion is in an end portion on a first side in the first slide direction, wherein the first facing portion limits a slide movement of the first rail member by being in contact with the first rail member inserted from a second side in the first slide direction; and the second facing portion is in an end portion on a first side in the second slide direction, wherein the second facing portion limits a slide movement of the second rail member by being in contact with the second rail member inserted from a second side in the second slide direction. the first game controller includes a first rail member configured for allowing the first game controller to be attached to the charging device; the second game controller includes a second rail member configured for allowing the second game controller to be attached to the charging device; the charging device includes: a support section; a first slide member in an area of the support section toward a first side in a predetermined direction, the first slide member being configured to slidably engage with the first rail member in a first slide direction; and a second slide member in an area of the support section toward a second side in the predetermined direction, the second slide member being configured to slidably engage with the second rail member in a second slide direction; a support section; a first slide member in an area of the support section toward a first side in a predetermined direction, the first slide member being configured to slidably engage with the first rail member in a first slide direction; and a second slide member in an area of the support section toward a second side in the predetermined direction, the second slide member being configured to slidably engage with the second rail member in a second slide direction; the first slide member includes: a first facing portion having a first facing surface facing the second side; and a first terminal on the first facing surface, which first terminal is configured to be electrically connected to the first game controller; a first facing portion having a first facing surface facing the second side; and a first terminal on the first facing surface, which first terminal is configured to be electrically connected to the first game controller; the second slide member includes: a second facing portion having a second facing surface facing the first side; and a second terminal on the second facing surface, which second terminal is configured to be electrically connected to the second game controller; a second facing portion having a second facing surface facing the first side; and a second terminal on the second facing surface, which second terminal is configured to be electrically connected to the second game controller; the charging device includes a power supply control section configured to supply power, which is supplied from outside the charging device, to the first game controller via the first terminal and to the second game controller via the second terminal; the first facing portion is in an end portion on a first side in the first slide direction, wherein the first facing portion limits a slide movement of the first rail member by being in contact with the first rail member inserted from a second side in the first slide direction; and the second facing portion is in an end portion on a first side in the second slide direction, wherein the second facing portion limits a slide movement of the second rail member by being in contact with the second rail member inserted from a second side in the second slide direction.