The present invention provides a production method for biofuel based on a technology to convert carbon-dioxide as a carbon source through photosynthesis by photosynthetic microorganisms to biomass and produce biofuel of the biomass. The production method for biofuel of the present invention comprises a culturing process (S1) of culturing in a culture solution photosynthetic microorganisms which store oils, fats and carbohydrates in cells of the photosynthetic microorganisms, an oil and fat conversion process (S2) of converting the carbohydrates stored in the cells of the photosynthetic microorganisms cultured in the culture apparatus to oils and fats, an extraction process (S3) of extracting the oils and fats out of the cells of the photosynthetic microorganisms, and a reforming process (S4) to reform the extracted oils and fats.