Plastic Plastic is a daily human need, excessive use of plastic has caused serious environmental problems and health problems for humans. The manufacturing process is not environmentally friendly and takes 10 - 50 years to decompose naturally by soil microbes. Therefore, the problem of plastic waste needs a solution, namely waste processing using the combustion pyrolysis method without air pollution which produces by-products in the form of liquids, steam, and solids that have economic value. In this study, Low Density Polyethylene (LDPE) Polyethylene terephthalate (PET) plastic was processed by the pyrolysis method with variations in temperature (70,90,100,125,145) °C and processing time (30,60,90,120,150) minutes. For liquid output, the mass produced from PET (574 grams) is more than that of LDPE (197 grams) obtained at a temperature of 100 °C. The density of the oil produced by pyrolysis in Low Density Polyethylene (LDPE) is close to the density value of gasoline fuel of 731.250 kg/m3, while PETE plastic which is close to the density of gasoline is 767.213 kg/m3 and 784.615 kg/m3 the density is close to ethanol fuel. For solid output, the mass produced from PET (588 grams) is less than LDPE (1740 grams) The solid output quality of LDPE is more sturdy and strong than PET.