This paper firstly reports a highly reliable MEMS-switch employing a CNTs-network lubricant in the contact-area. By covering the contact-area with the CNTs-network, we achieved more than an order of magnitude extension in the lifetime of the MEMS-switch. We determined that this drastic improvement in the reliability arises from the compressibility of the CNTs-network, generating remarkable contact-area widening with suppressed adhesive interaction at the contact interface. We also observed that the highly flexible CNTs-network does not deteriorate high-speed operation of the device. The proposed switch exhibited a lifetime more than 10 times longer under hot-switching condition than a device without CNTs.