We have developed a novel junction pseudomorphic high electron mobility transistor (JPHEMT) with a gate-drain and gate-source (gate-drain/source) recessed structure, Recessed JPHEMT (R-JPHEMT), and achieved the small off-capacitance (Coff) of 161fF/mm by using the recessed structure as well as keeping the low on-resistance (Ron) of 1.4ohm-mm with a buried pn junction gate. In Addition, we achieved a significant improvement in harmonics and inter-modulation distortions (IMD) compared with the ones in a conventional JPHEMT. Thus, this device has an excellent Quality factor (Q), the product of Ron-Coff, and low distortion characteristics as a switching device. The very low Q makes it possible to design a multi-throw switch, SP10T. The IMD2 and IMD3 of this SP10T switch are below -110dBm with low insertion loss. This novel device has been developed by using the low cost, 6inch, high-volume mass production technology.