The present invention provides a
bioplastic substrate that is sufficiently thin, resistant to deformation by heat, has a
smooth surface, and is suitable for use as a substrate for electronic devices, as well as a method for manufacturing the same. [Solution] A
bioplastic substrate having a film-like shape containing
cellulose acetate
propionate resin, with a thickness of 0.1 mm to 1.0 mm and a
surface roughness (SRa) of 30 nm or less, wherein a 20 mm square test piece taken from the
bioplastic substrate is placed on a horizontal mounting surface and heated at 80°C for 15 minutes, and the maximum distance between the mounting surface and the surface of the test piece facing the mounting surface is 0.3 mm or less.