A portable electronic device comprises an upper member, a lower member having two guiding grooves, two supports and two connecting members. One end of each support is pivoted to the upper member with a first pivot portion. The other end of each support is pivoted to the lower member with a second pivot portion. One end of each connecting member is pivoted at one side of the upper member, and the other end thereof is restricted in the guiding groove and capable of reciprocally sliding in the guiding groove.