A desktop-type air curtain device capable of being installed on a desk to protect healthcare workers from infectious diseases was developed. Pseudo-exhaled air containing aerosol particles emitted from a mannequin was blown toward the air curtain generated by the air curtain device. The aerosol blocking effect of the air curtain device was investigated using particle image velocimetry measurements. Air curtain flow was maintained inside the gate of the air curtain device. The aerosol particles approaching the air curtain device were observed to abruptly bend towards the suction port without passing through the gate, signifying that the aerosol particles were blocked by the air curtain flow.