PURPOSE: A display device is provided to effectively discharge heat generated from a driving chip by forming a heat dissipation part on a circuit board. CONSTITUTION: A sealing member(102) is formed to face a substrate(101). An extension part(101a) is formed on one side of the substrate in order to be extended longer than the sealing member. A display part(150) is arranged between the substrate and the sealing member. A driving chip(105) transmits an electric signal to the display part. A circuit board(140) comprises a heat dissipation part(160) for discharging heat generated from the driving chip.
