A microarrayer system was developed mainly for manufacturing DNA chips. The 3-axis robot was designed to automatically collect samples from 96-or 384-well microtiter plates using up to 16 simultaneously moving pens and to deposit them on a surface-modified slide glass. This is followed by a wash/dry operation in a clean station. The cycle is repeated with a new set of samples, This system can deposit cDNA or oligonucleotides with spot intervals of $150{;}mu extrm{m}$ and the spot size of $80mu extrm{m}$, thus allowing a high density DNA chip containing about 5,000 spots per $ extrm{cm}^2$. The entire procedure is controlled by the Visual C++ program that was written in our laboratory by using a personal computer with Pentium 100 CPU.