Indiana University-Purdue University Indianapolis (IUPUI) / Scientific realism and antirealism are two main views in the philosophy of science regarding the status of unobservable entities in science and whether we have good epistemic reasons to believe that our current successful scientific theories are (approximately) true. Briefly, the former claims that our scientific theories are (approximately) true and unobservable entities these scientific theories postulate exist. On the other hand, the latter claims that we do not have good epistemic reasons to believe that our scientific theories are (approximately) true and that unobservable entities our scientific theories postulate exist. The scientific realism has two primary tenets, one axiological (i.e., science should seek truth) and the other epistemological (namely, our current successful theories are (approximately) true). In this thesis, the issue has been examined from standpoint of the account of Peirce’s philosophy of science, more accurately based on his understanding of reality, truth and basic idealism. In the first chapter, I outline the main points of the debate from the perspectives of both sides. In the second chapter, I give reasons why the scientific realists’ argument is not convincing. In the third chapter, I attempt to draw an accurate picture of the account of Peirce’s views on the nature of scientific theories. In the last chapter, I make a case for scientific realism from the Peircean account of philosophy of science. I have claimed why the current debate cannot be settled without accepting a kind of Peirce's basic idealism and his understanding of reality. I think both scientific realists and antirealists accept a kind of naïve realism. This is the main reason why it is not possible to settle the debate from their standpoints. In order to overcome this issue, I attempt to develop a more sophisticated realism based on Peirce’s understanding of reality, truth and basic idealism.