A planar monopole antenna was designed for 60 GHz band ultra-small and low-cost front-end modules using organic substrates. The planar monopole antenna was simply patterned on the top layer substrate of the module. Simulated results showed that bandwidth and gain of the antenna were sufficient for 60 GHz wireless personal area network (WPAN) system. We fabricated and evaluated the module. Maximum actual gain of 5.1 dBi at 63 GHz was measured even though single element and very easy structure antenna was used. Although lossy substrate was used for cost reduction, the antenna patterned on organic substrates for 60 GHz band module had enough potential for being used as a low-cost and simple construction antenna for 60GHz band WPAN modules.