Operation of a cesiated rf-driven negative hydrogen ion source was initiated in September 2014 in response to the requirements of beam current upgrade in J-PARC linac. Delivery of the required beam current from the ion source to the J-PARC accelerators has been successfully performed. In 2016-2017 campaign, continuous operation of the ion source for approximately 1450 hours (from January to March 2017) was achieved with beam current, macro pulse width and repetition of 45 mA, 500 $\mu$s and 25 Hz, respectively. We present the operation status of the ion source as well as R&D activities at a new test stand  equipped with a set of an H$^-$ ion source and an LEBT which is almost the same configuration as the J-PARC linac.
 H. Oguri et. al., AIP Conf. Procs., Vol. 1869, 030053 (2017).