the invention relates to a method for manufacturing a semiconductor device with a resistor having a high resistance . in the invention , a first polycrystalline silicon layer is first formed to connect with an electrically connecting portion formed in a semiconductor substrate . next , a second polycrystalline silicon layer containing oxygen is formed on the first polycrystalline silicon layer . and then , an oxide formed between the two polycrystalline silicon layer is removed by annealing .