The relationships between software requirements work as the basis for several important software activities, such as change impact and developing cost analysis. Multiple types of relationships are mentioned in the RE literatures including normal (e.g., dependency) and abnormal ones (e.g., conflicts), and most of the existing work usually focus on the identification of one specific relationship. We collect and analyze the relations in the RE literatures, and find some common semantic elements of functional requirements are involved in the definition of multiple types of relations. Thus, to support automatically identifying diverse relationships, we propose our definition of the micro-level semantic constitution of functional requirement (M-FRDL), and one automatic approach for the element extraction, named by Micro-level Semantic elements Analyser of functional requirement (MISA). The experiments with three open requirement datasets show that our MISA can correctly identify about 94.93% elements of requirements on average.