By situating a mixing pot in a junction of a first solution and a second solution or after the junction in a channel to temporarily retain these solutions, and situating an analysis sensor downstream from the mixing pot to detect the result of reaction of the first solution and second solution, heterogeneous solutions are mixed so as to react within the channel, and chemical analysis of one of the solutions is performed. According to this system, before the solutions have fully flowed through the remainder of the channel following the junction, the solutions are mixed uniformly at once by the turbulent and vortex flow generated within the mixing pot.