A radio communication apparatus which performs a direct communication with a counter radio communication apparatus, said radio communication apparatus comprising: a radio section configured to receive from the counter radio communication apparatus, a first radio signal which contains a first transmission power setting value as a setting value of power at transmission from the counter-radio communication apparatus, and to measure a first reception power value as a power value at reception of said first radio signal; and a transmission power control section configured to determine a second transmission power setting value as a setting value of power at transmission of a second radio signal to the counter radio communication apparatus based on said first transmission power setting value and said first reception power value, wherein said radio section transmits said second radio signal, which contains said second transmission power setting value, to the counter radio communication apparatus with the transmission power indicated by said second transmission power setting value; characterised in that said transmission power control section relates said first transmission power setting value and said first reception power value to an identifier data indicating said counter radio communication apparatus, to store in a peripheral automobile table, and refers to said peripheral automobile table based on said identifier data, to determine said second transmission power setting value; and wherein said transmission power control section: stores a transmission power setting table, in which said first transmission power setting value, said first reception power value, and said second transmission power setting value are related to each other as a combination data; refers to said peripheral automobile table based on said identifier data, to acquire said first transmission power setting value and said first reception power value; and refers to said transmission power setting table based on said first reception power value and said first transmission power setting value, to determine said second transmission power setting value, wherein said first transmission power setting value and said reception power measurement value stored in said transmission power setting table are grouped into one of a plurality of categories, respectively; and said second transmission power setting value is determined on the basis of the respective categories of said reception power measurement value and said first transmission power value. a radio section configured to receive from the counter radio communication apparatus, a first radio signal which contains a first transmission power setting value as a setting value of power at transmission from the counter-radio communication apparatus, and to measure a first reception power value as a power value at reception of said first radio signal; and a transmission power control section configured to determine a second transmission power setting value as a setting value of power at transmission of a second radio signal to the counter radio communication apparatus based on said first transmission power setting value and said first reception power value, wherein said radio section transmits said second radio signal, which contains said second transmission power setting value, to the counter radio communication apparatus with the transmission power indicated by said second transmission power setting value; characterised in that said transmission power control section relates said first transmission power setting value and said first reception power value to an identifier data indicating said counter radio communication apparatus, to store in a peripheral automobile table, and refers to said peripheral automobile table based on said identifier data, to determine said second transmission power setting value; and wherein said transmission power control section: stores a transmission power setting table, in which said first transmission power setting value, said first reception power value, and said second transmission power setting value are related to each other as a combination data; refers to said peripheral automobile table based on said identifier data, to acquire said first transmission power setting value and said first reception power value; and refers to said transmission power setting table based on said first reception power value and said first transmission power setting value, to determine said second transmission power setting value, stores a transmission power setting table, in which said first transmission power setting value, said first reception power value, and said second transmission power setting value are related to each other as a combination data; refers to said peripheral automobile table based on said identifier data, to acquire said first transmission power setting value and said first reception power value; and refers to said transmission power setting table based on said first reception power value and said first transmission power setting value, to determine said second transmission power setting value, wherein said first transmission power setting value and said reception power measurement value stored in said transmission power setting table are grouped into one of a plurality of categories, respectively; and said second transmission power setting value is determined on the basis of the respective categories of said reception power measurement value and said first transmission power value.