Microlensing is a relatively new technique for searching for extrasolar planets. One of its main strengths is its ability to detect planets with masses as low as that of Earth. The MOA (Microlensing Observations in Astrophysics) project is a joint New Zealand-Japan collaboration that has been in operation since 1995. I will describe the microlensing technique together with some its special challenges. I will also describe the work of MOA since 1995 and describe the propects for the future with the new MOA 1.8m telescope.<br />