A flow channel instrument as a structurally simple and easy-to-use viscometer which is used for evaluation of the viscosity of liquid foods was operationally modified with an opening-variable gate in the channel path functioning as a valve for flow control. In the modified instrument, Newtonian and non-Newtonian test liquids were employed for flow experiments. The former liquid was purely viscous and the latter liquids were both of elasticities higher and lower relative to viscosity. The related flows were examined to assess the effect of the gate on the flow in consideration of the process swallowing liquid foods. The functional channel instrument revealed that the flow behavior differed depending on the relative elasticity of the liquid.