The motions of the airflow and particles induced by a moving operator in a cleanroom were studied numerically. This situation is classified as a kind of moving boundary problem, and a Galerkin finite element formulation with an arbitrary Lagrangin-Eulerian kinematic description method is adopted to analyze this problem. Two different moving speeds of the operator under Reynolds number Re = 500 and Schmidt number Sc = 1.0 are taken into consideration. The results show that circulation zones, which are disadvantageous to remove the particles, are observed around the operator and near the worktable and that the operator usually prevents the removal of the particles. The relatively slow moving speed of the operator is beneficial to remove the particles. These phenomena are quite different from those regarding the moving operator as stationary in the cleanroom.