A droplet inspection method using a 2-dimensional (2D) image of a droplet includes ejecting ink onto a substrate based on a preset inspection pattern using an inkjet head, acquiring a 2D image of the droplet of ink ejected to a plurality of positions on the substrate using a measurement camera located on a side surface or above the substrate, and calculating a diameter of the droplet from the 2D image and calculating a volume of the droplet using the calculated diameter of the droplet and a pre-measured contact angle of the substrate for inspection.