In order to alleviate the affect of particles generated during operation of an elevation mechanism of a substrate conveyer means on the substrate that is transported in a substrate processing apparatus, a partition wall having a slit-like hole is provided in a casing that forms the outer housing of the elevation mechanism, whereby the casing is divided into a first chamber and a second chamber. A conveyer main unit holding a wafer is fixed to a rod-like support member. The support member has its end supported by a guide shaft. The guide shaft and a driving mechanism to move the support member upwards and downwards are provided in the first chamber. The support member descends and ascends along the guide shaft. A fan is disposed in the second chamber. A discharge outlet is formed at the bottom plane of the second chamber. By driving the fan, the atmosphere in the first chamber is attracted via the hole of the partition wall, whereby particles generated during the elevation of the conveyer main unit are discharged from the discharge outlet via the second chamber.