A connection module for a portable device having a reduced thickness and a slimmer shape. The connection module includes a case, an upper plug connection terminal unit, and a lower plug connection terminal unit. The case includes an upper portion and a lower portion. The upper plug connection terminal unit includes a plurality of upper connection terminals disposed along the upper portion. The lower plug connection terminal unit includes a plurality of lower connection terminals disposed along the lower portion. The plurality of lower connection terminals are spaced apart from the plurality of upper connection terminals and alternately arranged at staggered positions such that the plurality of upper and lower connection terminals engage each other when positioned on a same plane.