An operation device for controlling sliding cover of portable electronic product includes first, second and third magnetic members, a transmission unit and an operation unit. The third magnetic member is connected to the transmission unit and includes first and second magnetic polarities. The operation unit drives the transmission unit and the two magnetic members are fixed to the first and second positions of the sliding cover. When the operation unit is operated, the third magnetic member is rotated so that the first magnetic polarity of the third magnetic member is impulsive to the first magnetic member to open the sliding cover, or the first magnetic polarity of the third magnetic member is impulsive to the second magnetic member to close the sliding cover.