The Industry Ministry said on Thursday its manufacturing production index (MPI) in May rose 2.6 percent from a year earlier. A Reuters poll had forecast a rise of 1.85 percent.
In April, output rose a revised 0.89 percent from a year earlier, instead of the 1.54 percent reported a month earlier.
Industrial goods accounted for nearly 79 percent of total exports in May, which declined 4.4 percent from a year earlier, customs data showed.
May's output increase was led by autos, air conditioners and rubber products.
Capacity utilisation was at 67.45 percent in May, up from April's revised 59.52 percent.
Exports have contracted in each of the past three years. The central bank has forecast shipments will fall 2.5 percent this year, down from a 2 percent drop projected earlier, while it still expects the economy to grow 3.1 percent.