The prices of goods traded between companies rose for the eighth month in a row with the latest result being the largest increase since an 8.1 percent increase recorded in January 1981.
Prices of petroleum and coal products jumped 44.5 percent, reflecting higher commodity prices.
As many COVID-19 restrictions were lifted, demand for energy and raw materials was boosted with the recovering economies. According to the BOJ data, lumber and wood prices soared 57 percent, iron and steel prices advanced 21.8 percent, and prices for nonferrous metals surged 31.4 percent.
Electricity, gas, and water bills rose 10.9 percent. Electricity prices normally track higher oil prices with a delay.
Import prices also marked a record 38 percent increase, and export prices increased 13.7 percent. Both figures are in yen terms.
Despite the surging wholesale prices, the BOJ maintained its monetary easing to attain its 2 percent inflation target, as it evaluated that the inflationary pressure was not as high as in other advanced economies.
The core consumer prices, a key measure of inflation, were only modest compared with wholesale prices since Japanese companies have been reluctant to pass on higher costs to consumers to protect demand recovering from the COVID-19 pandemic.
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