I will explain the theory of software metrics, which provides the basis for software quality, and basic measurements such as size, complexity, and defects, as well as the process of quality evaluation and improvement targeting design and source code in embedded software development. Then, "pitfalls" and "tips" in practice will be explained, and goal-oriented measurement will be taken up as a particularly important tip, and the specific method Goal-Question-Metric (GQM) and its extension GQM+Strategies will be explained. In addition, as a case study, the Waseda Software Quality Benchmark, a quality reality obtained by using the ISO/IEC 25000 series of international quality standards, will be introduced.