This chapter investigates university students’ and lecturers’ attitudes towards English-medium instruction (EMI) and ‘English’ used in EMI classes at a Japanese university. With the progress of globalization, English is increasingly used as a lingua franca (ELF) among people from diverse linguacultural backgrounds in a range of international contexts. This trend is also observable in the context of Japanese tertiary education, where EMI is increasingly promoted by the government, aiming to internationalize universities by attracting more international students and make Japanese students ‘global’ human resources. The actual conditions of EMI and the use of ‘English’ in EMI classes, however, are not usually explicitly discussed, particularly by taking into account participants’ views and the role of ELF in the globalized world. Accordingly, this chapter explores students’ and lecturers’ voices in EMI classes from an ELF perspective. The qualitative analysis of questionnaire responses reveals that while the students place more importance on language-learning through EMI, although not exclusively, there being a certain difference among the different students’ populations, the lecturers tend to focus more on content teaching. Furthermore, it was also found that the ‘E’ of EMI is still widely associated with ‘native’ English among the students, albeit quite often subconsciously.