This paper presents a simple and low-cost micro direct borohydride fuel cell (DBFC) using a mixture of a fuel (sodium borohydride, $NaBH_4$) and a liquid electrolyte (potassium hydroxide, KOH) in order to improve three-phase contact in micro fuel cells. It consists of an anode, cathode, and a fuel chamber for the liquid mixture of the fuel and the electrolyte. For anode catalysts, gold (Au) was sputtered on a Pyrex$^{(R)}$ glass, and manganese dioxide supported on carbon ($MnO_2/C$) was coated on nickel foam for cathode catalysts. The $NaBH_4$ and 1 M KOH were used as the hydrogen source and electrolyte respectively. The DBFC has a simple configuration without auxiliary devices and is cost effective because a platinum catalyst and ion exchange membranes were not used. The size of the DBFC was $20{ imes}14{ imes}5mm^3$, and the active area was $10{ imes}10;mm^2$. The DBFC showed a maximum power of 1.18 mW at 0.29 V, and three serially connected cells illuminated two LEDs for one hour without refueling and any auxiliary devices.