Semi-supervised learning utilizing both labeled and unlabeled data has recently made significant progress; however, while semi-supervised image classification research has been actively conducted and solved many problems, semisupervised semantic segmentation research still has some problems that need to be solved. In this work, semi-supervised semantic segmentation, which requires more annotation work than other tasks such as classification, was investigated because labels are required on a pixel-by-pixel basis. Consistency regularization based on input image perturbation, feature perturbation, and network perturbation in the semi-supervised learning approach showed significant performance improvement. In particular, consistency regularization through network perturbation showed excellent performance in semi-supervised semantic segmentation. However, important challenges remain. Due to pseudo-label bias, inaccurate pseudo-labels for unlabeled data can negatively affect training, which causes more serious problems in semi supervised segmentation tasks. This study mitigates the pseudo-label bias issue by expanding the network perturbation-based method, which has shown excellent results, through a simple ensemble strategy. In addition, this simple method shows improved prediction performance. The results of this study outperform previous state-of-the-art methods and achieve state-of-the-art semi-supervised segmentation performance. The proposed method can be practically applied to the handson data science domain that hardly obtains sufficient class-labels (e.g. medicine, manufacturing, etc.).