There is provided an electrical connection device (100) including a male portion including a head (21) having a groove for insertion of a driver, and a body portion (24) having a spirally penetrating first guide hole (26a) formed from a lower end and a second guide hole (26b); a female portion (116) having a hole portion (118) into which the body portion (24) is inserted; an elastic portion (40) to be disposed on an outer circumference of the body portion (24) when the body portion (24) is inserted into the hole portion (118); and a movable body (30) which is disposed below the elastic portion, and engages and penetrates through the first guide hole (26a) when the body portion (24) is inserted into the hole portion (11), in which a first conductive member (50) and a second conductive member (60) are interposed between an upper end of the elastic portion (40) and the head (21), and with the movable body (30) engaged in the first guide hole (26a), as the head (21) rotates to a predetermined rotation angle relative to the hole portion (118), a biasing force of the elastic portion (40) is increased due to a rise of the movable body (30) in contact with a lower end of the elastic portion (40), and when a rotation angle of the head (21) relative to the hole portion (118) exceeds the predetermined rotation angle, the movable body (30) engages in an end portion (29) of a second guide hole (26b) leading to the first guide hole (26a), the second guide hole being provided in a direction in which the biasing force is reduced, to suppress rotational movement of the movable body (30) relative to the body portion (24).