Provided is a manufacturing method for a glass sheet, including: fusing a glass ribbon (G) by irradiating the glass ribbon (G) with a laser (L) along a preset cutting line (X), which is a boundary between a product portion (G1) to be used as a product and a non-product portion (G2) to be discarded, and jetting an assist gas (A) onto molten glass (M) generated by melting the glass ribbon (G) through heating with the laser (L) so as to remove the molten glass (M) by scattering the molten glass (M); and breaking the non-product portion (G2) so as to discard the non-product portion (G2), the assist gas (A) being jetted from the product portion (G1) side with respect to the preset cutting line (X), to thereby cause scattered pieces of the molten glass (M) to adhere to the non-product portion (G2) as pieces of dross (D).