A solid state drive apparatus includes a casing including a top plate, a bottom plate, a first sidewall, and a second sidewall. A first substrate is disposed inside the casing. At least one first semiconductor chip is mounted on the first substrate. A second substrate is disposed inside the casing. At least one second semiconductor chip is mounted on the second substrate. A heat dissipation structure is disposed between the first substrate and the second substrate and includes a lower heat dissipation panel contacting the at least one first semiconductor chip. An upper heat dissipation panel contacts the at least one second semiconductor chip. An air passage is provided between the lower heat dissipation panel and the upper heat dissipation panel and extends from the first sidewall of the casing to the second sidewall.