Abstract: A computer has a casing that accommodates a main board having a heat generating component that generates heat therein. The computer includes an internal heat discharging part disposed in the casing and coupled with the main board to discharge a first portion of the heat generated by the heat generating component, an external heat discharging part provided on an external surface of the casing to discharge a second portion of the heat generated by the heat generating component, and a heat transmission part to transmit the first and second portions of the heat generated by the heat generating component to the internal and the external heat discharging parts, respectively, such that the first and second portions of the heat generated from the heat generating component is discharged through the internal and the external heat discharging parts, respectively. Accordingly, the computer has a simple structure and assembly and an improved heat discharging efficiency.